Dental matrix.



Patented June 3, I902. W. CRENSHAW. DENTAL MATRIX (Application filedJuly 27, 1901.)

(lo Iodel.)

' [NVENTOR UNITED STATES PATENT OFFICE.

WILLIAM CRENSI-IAW, 0E ATLANTA, GEORGIA.

DENTAL MA R SPECIFICATION forming part of Letters Patent No. 701,799,dated June 3, 1902. Application filed July 27, 1901. Serial No. 69,985.(N model.)

T0 on whom, it mag concern.-

Be it known that I,"WILLIA1vI OnENsHAw, a citizen of the UnitedStates,residing at Atlanta, in the county of Fultonand State'of Georgia, haveinvented certain new and useful Improvements in Dental Matrices; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same. i

The object is to produce a matrix foruse in dental surgery which shallin a ready andefficient manner serve as a support while fillingdifiicult cavities in decayed teeth, especially such cavities asexten'd'through and include a portion of the lateral wall or surfacethereof and be capablefof adjustment to fit any-sized tooth. Cavities ofthis kind are most frequently found in the sideof a tooth next anadjacent tooth, and to cause these fillings to take the shape as nearlyas possible of that portion of the original tooth is an additionalobject.

A further object is to produce a dental matrix which shall admit of easyand quick adjustment between the teeth, shall fit closely and rigidlyaround and beyond the surfaces of the teeth to be filled, and be adaptedfor adjustment to fit various sizes of teeth, and, finally, which maybe'readily removed after the filling has been completed withoutdragging, lifting, breaking up, or in any way dis turbing the marginsor-conformation of said filling.

With these objects in-vi ew the invention consists in the various noveldetails of con struction and arrangement as will be hereinafter morefully described and claimed.

The invention consists, further, in the novel construction andcombination of parts of a dental matrix hereinafter described andclaimed. 1 I

In the accompanying drawings, in which like letters ofreference-indicate corresponding parts, I have'illustrated one form ofembodiment of my invention, it being understood that I do not limitmyself or the scope of the invention to the form shown, as variouschanges and modifications may be devised without departing from thespirit thereof.

In the drawings, Figure 1 is a plan View in elevation, showing the partsof my improvedmatrix assembled and ready for use. Fig. 2 is a side viewin elevation of the same looking in the direction of-thearrOW a; ofFig. 1. Fig. 3 is a similar view showing the parts in position forremoval'from between the teeth. Fig. 4 is -a view in end elevationlooking in the direction of the arrow y, Fig. 1. Fig. dis adetached'view of the metal tubes or distance-pieces shown' lin variouslengths. Fig. dis a detail View of one end of the strips or bands A.Fig. 7 shows'in detail the construction of one of the threaded nuts.Fig. 8 is a view in perspective, showing my matrix placed in positionbetweentwo teeth and ready for use; and Fig. 9 is a similar view inwhich the device is applied to smaller teeth, as the bicuspids, a longerdistance-piece beingused.

Referring to the drawings, the matrix is constructed usually of twometal bands or strips A, which may preferably be quite thin and flexibleand are formed or adapted to be formed intooppositelydisposed curves orloops. 'Atone end each band is formed with a socket or stirrup a,cylindrical in form and constricted at the outer end, which sockets areto receive the metal tubes or distancepieces B. Theseltubes B are madein yarious lengths'and maybe tapered or reduced at one end, as atb, sothat when assembled a suitably-shaped wedge or other device'm'ay beintroduced forthe purpose of separating the strips or bands, as byinserting the same over or under the bar'or pin and between the flexiblestrips of bands A; thus forcing these bands against the cervical marginwhen this is necessary. These tubes are preferably secured in positionby a removable pin G, upon which latter they have a rotative or pivotalmovement. The other end of each strip A may be doubled upon itself toform a loop a thefree end of which is slitted, as zit-0, to receive theneck d of the tapped and threaded nut 01*, Figs. 6 and 7. Each nut isheld in the t'oeof the loop a by the headd In order to place a tensionon the strips A, a screw-bar D may be provided, havingoppositely-threaded ends d adapted to engage the nuts 61 secured to thestrips A, this bar beingpreferably squared throughout the greater partof its length and having a reduced portion d near its center to permitinsertion of the wedge or other device aforementioned over or under thesame and to receive the end of a strip or tongue E, the opposite end ofwhich strip is provided with a perforation, through which passes the pin0. The strip E is thus pivotally mounted between the adjacent ends ofthe tubes or distance-pieces B and is adapted to be drawn down betweenthe strips A to effect separation thereof where the device is beingapplied between two teeth both of which are to be filled, the tongue orstrip creating a space between the strips, so that when it is withdrawnthey will spread somewhat to facilitate their removal from around eachtooth.

Each of the three strips above mentioned is formed with a similaroutline, as shown in Fig. 3, where it appears that the lower edge of thestrips is provided with a bulge a adapted to extend downward between thecervical margin of the tooth and the gum to form an efiectual closurefor the side of the cavity adjacent thereto and also for holding downthe rubber-dam septum. The screwbar D is provided with perforations dextending in directions at right angles to each other to receive a keybar or pin for tightening or loosening said bar within the nuts. WVhenthe cavity to be filled is located in a large tooth, such as a largemolar, two of the smaller tubes B or two of moderate length will beemployed, as shown in Fig. 8, in order to lengthen or let out the bandsor strips A to permit them to extend around the tooth when the device isin position. WVhen, however, the cavity to be filled is in a smalltooth, such as the small molars or bicuspids, the longest size of thebar B will be employed, thereby taking up or shortening the bands A.WVhen the proper tubes have been inserted and the device is ready forapplication between the teeth, the bands are inserted between the toothto be filled and the adjacent tooth, with the central strip E preferablyin a closed position. The screw-bar D is then manipulated to force theends of said bands apart, thereby placing them under tension and causingthem to conform to the outline of the tooth. After the filling has beencompleted the central strip may be removed and the screw-bar D loosened,thereby relieving the tension of the bands A and the pressure upon theteeth and the filling,when the whole device maybe removed from itsposition without in any way dragging out, breaking up, or disturbing themargin or conformation of the filling, which will be found to possess asnear as possible the original outline or contour of the perfect tooth.

Many advantages are secured by constructinga dental matrix according tomy invention. Thedevice maybe easily and quickly arranged to fit or toconform to teeth of any size, and may be quickly adjusted in positionfor use, and is practically in one piece when thus adjusted. The metalstrips or bands which form the matrix or support for the filling properextend practically three-fourths around each tooth and by means of theadjustable tension maybe tightened to give to the filling a formapproximating the original shape of the tooth. The adjustment wheneffected is rigid and reliable, and after the filling has been effectedthe device maybe readilyand quickly removed without in any way injuringthe form or outline of the filling.

It is to be understood that one of the distance-pieces carried by thestrips or hands may, if desired, be stationary and yet be within thescope of my invention.

Owing to the fact that the nuts 01 may be detachable from the strips orbands A, these strips or bands may be readily replaced by others of likeor of varying width or may thus be interchanged at will. Also bywithdrawing the pin 0 one side of the matrix may be removed withoutdisturbing the remaining side, the part removed having a pivotalmovement upon the nut (1 as shown in Fig. 3. i

The parts are of course constructed, preferably, of non-corrosive metalor metal coated or plated in such a manner as to reflect light in thecavity and be practically unaffected by the moisture, the saliva, andother substances with which it comes in contact when in actual use.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. A dental matrix comprising flexible members, means connecting andcooperating with the members to cause the respective member to extendentirely around the inner surface of the tooth against which it bearsand approximating the contour thereof, and serving, also, to adjust saidmembers to cause them to bear toward each other to facilitate withdrawalfrom the teeth substantially as described.

2. A dental matrix comprising flexible members, means connecting andcooperating with the members to cause the respective member to extendentirely around the inner surface of the tooth against which it bearsand approximating the contour thereof, and serving, also, to adjust saidmembers to cause them to bear toward each other to facilitate withdrawalfrom the teeth, additional means carried by the members for placing themunder tension, and means operating between the members for effectingadditional pressure of a member upon a contacting tooth, substantiallyas described.

3. A dental matrix comprising members of reverse curvilinear form, meansconnecting with the members and adapted to cause them to approximate thecontour of the portion of the tooth against which each bears, means foreffecting tensioning of said members, additional means for effectingseparation thereof while tensioned, and means for efiecting displacementof said members to cause them to bear toward each other tofacilitatewithdrawal from the teeth, substantially as described.

4. A dental matrix comprising flexible members, means connecting andcooperating with the members to cause them to approximate the contour ofthe portion of the tooth against which it bears, and to bear toward eachother to facilitate Withdrawal from between the teeth, and a strip ortongue for insertion between the members for effecting separationthereof while bearing against the teeth, substantially as described.

5. A dental matrix comprising flexible members carrying means serving tocause the respective members to extend around the inner surface of thetooth against which it bears and approximating the contour thereof, andserving, also, to adjust said members to cause them to bear toward eachother to facilitate withdrawal from between the teeth, and means forvarying the bearing-surface of said members for application todiflerentsized teeth, substantially as described.

6. A dental matrix comprising two flexible, oppositely-disposed membersadapted to be placed between adjacent teeth, a support constituting aconnection between said members and carrying means for effectingadjustment of the members to cause them to approximate the contour ofthe inner surfaces of the teeth against which they bear to give the faceof the filling therein the general outline of the tooth and serving alsoto adjust said members to cause them to bear toward each other and awayfrom the filling to facilitate withdrawal therefrom, substantially asdescribed.

7. A dental matrix comprising flexible members adapted to be placedbetween adjacent teeth and formed, at contiguous ends, with tube-pieces,a distance-ad j usting device disposed between the tube-pieces, andmeans at the opposite ends of the members for adjusting them toapproximate the contour of the tooth and, also, cause them to beartoward each other to facilitate withdrawal from between the teeth,substantially as described.

8. A dental matrix comprising members of reverse curvilinear form andprovided at one end with a distance-piece, oppositely-threaded nutssecured at the free ends of said members, and an oppositely-threadedscrew-bar adapted to engage said nuts to form an adjustable tension-barfor said members, substantially as described.

9. A dental matrix comprising members of a reverse curvilinear form andadapted to be placed between adjacent teeth, means carried by the outerends of the members for effecting tensioning of the same,distance-pieces connecting with the inner ends of the members, one ofsaid distance-pieces being replaceable, the parts being disposed andadapted to cause the members to bear toward each other to facilitatewithdrawal from the teeth, substan= tially as described. a 10. A dentalmatrix comprising members of reverse curvilinear form and adapted to beplaced between adjacent teeth, means connecting with the members fortensioning them, said members being provided at contiguous ends withdistance pieces, and a strip or tongue having a pivotal connection withone of said pieces and adapted to extend between said members,substantially as described.

11. A dental matrix comprising flexible members adapted to be placedbetween adjacent teeth and formed, at contiguous ends, with tube-pieces,a distance-adjusting device,-

disposed between the tube-pieces, a pin adapted to engage thetube-pieces and distanceadjusting device to maintain them in relativeposition, and means engaging the remaining ends of said members forplacing the same under tension, substantially as described.

In testimony whereof I affix my signature in the presence of twosubscribing witnesses.

WILLIAM CRENSI-IAW. Witnesses:

EDMUND I-I. PARRY, AYLET'I. T. HOLTZMAN.

